You are given a table, BST, containing two columns: N and P, where N represents the value of a node in Binary Tree, and P is the parent of N.
You are given a table, BST, containing two columns: N and P, where N represents the value of a node in Binary Tree, and P is the parent of N.
Write a query to find the node type of Binary Tree ordered by the value of the node. Output one of the following for each node:
- Root: If node is root node.
- Leaf: If node is leaf node.
- Inner: If node is neither root nor leaf node.
Sample Input
Sample Output
1 Leaf
2 Inner
3 Leaf
5 Root
6 Leaf
8 Inner
9 Leaf
Explanation
The Binary Tree below illustrates the sample:
———-SOLUTION———-
MYSQL
SELECT N, CASE WHEN P IS NULL THEN 'Root' WHEN N IN (SELECT P FROM BST) THEN 'Inner' ELSE 'Leaf' END FROM BST ORDER by N;
MS SQL SERVER
select N, case when P is null then 'Root' when (select count(*) from BST where P = B.N) > 0 then 'Inner' else 'Leaf' end from BST as B order by N ;